Research On The Control Technology Of Three-phase Voltage Source PWM Rectifier

Three-phase voltage source PWM Rectifier has been widely used in the field of power conversion because of its simple control structure,controllable power factor etc.Direct current control based on double closed-loop of voltage and current is widely employed in three-phase voltage source PWM rectifier.The traditional proportion integral(PI)regulator in synchronous rotating frame is easy to generate inrush current during start-up period.Besides,the bus voltage will appear large fluctuation at the moment of load disturbance.When using traditional direct power control strategy in three-phase voltage source PWM Rectifier Systems,there are some deficiencies that reactive power has incontrollable area and DC output voltage has large fluctuation in controlling of voltage source PWM rectifier.As a result,these problems will lead to increase the stresses on switches and influence device’s service life and system reliability.It even causes the serious problem of electromagnetic interference.To solve these problems,this paper conduct research on a three-phase voltage source PWM Rectifier,works are as follows:Firstly,this paper analyzed topology and the basic principles of the three-phase voltage source PWM rectifier and established mathematics model.And even it deeply analyzed the relationship between the variables to find out the control law.This work laid the groundwork for the next research.On the one hand,the three-phase voltage source PWM rectifier with direct current control is easy to generate inrush current during start-up period,and it is easily affected by load disturbance.For these issues,this paper proposed a new double closed loop control strategy to effectively restrain inrush current.Besides,According to the power relations during the instantaneous of load disturbance,this paper proposed a method of new feed-forward control of load current to improve the capability of anti-load disturbance and the reliability of system operation.The simulation model is established in MATLAB/Simulink,the simulation results verify the correctness of the theory analysis.On the other hand,when using traditional direct power control strategy in three-phase voltage source PWM Rectifier Systems,there are some deficiencies that reactive power has incontrollable area and DC output voltage has large fluctuation in controlling of voltage source PWM rectifier.This paper came up with double switching sector table direct power control strategy to solve some shortcomings of traditional control strategy applied in three-phase voltage source PWM rectifier.Three-phase voltage source PWM Rectifier direct power control system simulation model is established in MATLAB/Simulink.The research results suggest that the improved direct power control strategy eliminates the incontrollable area of reactive power,improves the dynamic characteristics of the system.Finally,the experimental prototype is designed by using ARM processor STM32F103ZET6 as the microcontroller to achieve,the experimental results verify the correctness and effectiveness of the theoretical analysis and design.